Optical measurement systems which use a laser triangulation sensor to obtain dimensional information about objects are known. For example, such systems may be arranged to determine the distance of objects from the sensor or the profile of objects within the field of view of the sensor.
Referring to FIG. 1, a conventional laser triangulation measurement device 1 comprises a light source 2 e.g. laser which is arranged to project a planar beam 4 (e.g. sheet) of light. The planar beam 4 is incident as a line 8 on an object or objects 5, 6 which lie in the field of view 7 of the device 1. Light reflected from the incident line 8 is collected by an imaging device 3, which may be a camera (e.g. having a charge coupled device (CCD) or an active pixel sensor (CMOS) device).
The images captured by the imaging device 3 are processed to determine a data representation of the physical geometry of the objects 5, 6. The processing may involved reference to a calibrated look up table or the like. Such processing is known.
FIG. 2 depicts two dimensions that may be determined using the data representation. The separation (gap G) or planar misalignment (mismatch or flush F) between adjacent surfaces may be determined, e.g. by performing suitable mathematical operations (e.g. line/radius fitting).
An example of a conventional optical triangulation sensor is the GapGun, manufactured by Third Dimension Software Limited.